The present invention relates to an electrophoresis gel migration apparatus for electrophoresis separation of a DNA or protein.
Conventionally, base sequence of a DNA has been determined in the way that the DNA was labeled by a radio isotope element and subjected to the electrophoresis gel separation before the separation pattern was transferred onto a film. However, the prior art technique mentioned above has the disadvantage that it is not only troublesome to use the radioactive label, but also it needs too much labor and time. To overcome such problems, a new real-time fluorescent label method has been recently used, as disclosed in the Japanese Patent Application Laid-Open 61-62843.
The fluorescent label method mentioned above uses slab gel, while a further new gel capillary electrophoresis method is now attracting attention. The gel capillary electrophoresis method provides a high-speed, high-sensitive analysis with use of a capillary filled with gel (hereinafter referred to as the gel capillary), as disclosed in the Analytical Chemistry, vol. 62, pp. 900-903, 1990.
The gel capillary electrophoresis is ordinarily made in the way that one capillary tube and a detection lens are built in a package to integrate. The capillary tube can be used repeatedly. However, it is usually discarded whenever it is used a few times as the gel is distorted during the operation. To make possible analysis of many samples at a time, there has been a disclosure that a multiple of gel capillaries are arranged for measurement. In the measurement, the multiple of gel capillaries are retained by the respective holders as disclosed in the BioTechniques, vol. 9, p. 74, 1990.
Any of those measurements having the capillary gel is made in the way that light is irradiated around the end of the capillaries to excite the fluorescent-labeled DNA passing there to emit fluorescence for detection of sample fragments. To make measurement at a high sensitivity and accuracy, the capillaries have to be set precisely.
In order to measure many DNA samples at a time to increase throughput, numbers of gel capillaries have to be arranged. The gel capillaries have to be replaced after a few times of measurement. This means that it must be easy to attach or detach the numbers of gel capillaries and to align their positions. The injection of sample into the gel capillaries has been made with the use of electric field into the ends of the gel capillaries put in sample wells. However, no reports have been made for good workmanship of injecting the sample if the numbers of gel capillaries should be arranged. This is one of the problems to be solved.
Distances of the gel capillaries should be longer with respect to easiness of the sample injection. But, they should be shorter for efficient measurement of the sample fragments. It therefore has been needed to develop an apparatus meeting both of these requirements.